Kinetic studies of the interaction of methyl orange with poly(L-lysine) by stopped-flow with circular dichroism detection
✍ Scribed by Kiyofumi Murakami; Takayuki Sano; Naohisa Kure; Katsushi Ishii; Tatsuya Yasunaga
- Publisher
- Wiley (John Wiley & Sons)
- Year
- 1983
- Tongue
- English
- Weight
- 485 KB
- Volume
- 22
- Category
- Article
- ISSN
- 0006-3525
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✦ Synopsis
The interaction of methyl orange with poly(L-lysine) was studied kinetically by the stopped-flow technique with CD detection, as well as by static CD titration experiments. In the static experiments, the differences observed in the polymer-to-dye ratio dependences of the CD spectra and absorption spectra suggested a t least two kinds of bound states of the methyl orange attached to the polymer. The kinetic experiments using the stopped-flow apparatus, however, revealed four distinct reaction processes. The reaction mechanism was elucidated from the concentration dependence of the time constant for each process as follows: the first process was attributed to the bimolecular binding step of methyl orange to the side chain of poly(L-lysine), the second and third processes were ascribed to the intramolecular reaction of the polymer-dye complex, and the fourth process was found to be the intermolecular aggregation of the polymer-dye complex. The origin of the stacking of methyl orange on poly(L-lysine) is discussed on the basis of the characteristics of the signal amplitudes obtained from the kinetic experiments for these processes.